Hydrochloric Acid → HCID 76282971, compound

Participants

Reaction Steps

To a solution of oxazole (217 mg, 3.14 mmol) in 8 mL dry THF under argon at room temperature was added BH3.THF (3.14 ml, 3.14 mmol), the reaction mixture was stirred at room temperature for 15 minutes, cooled down to −75° C. followed by slow addition of BuLi (1.96 ml, 3.14 mmol). The resulting reaction mixture was stirred at −75° C. for 30 minutes and a solution of 2-methyl-N-(oxetan-3-ylidene)propane-2-sulfinamide (CAN 1158098-73-7, 0.5 g, 2.85 mmol) in 4 mL dry THF was added. The reaction mixture was stirred at −75° C. for 30 minutes, then the reaction was let to warm up to room temperature and was stirred for 1 hour. The reaction was quenched by addition of 1 mL of an aqueous solution 7N ammonium chloride and reaction mixture was stirred for 15 minutes. The mixture was diluted with ethylacetate, poured into a separatory funnel and extracted with water. The organic phase was collected, dried over sodium sulfate and evaporated down to dryness to give a yellow oil. The crude material was used without any further purification. To a solution of the former crude oil (697 mg, 2.85 mmol) in methanol (9 ml) cooled down to 0° C. was added a 4.0M solution of hydrochloric acid in dioxane (2.14 ml, 8.56 mmol). The reaction mixture was stirred at 0° C. for 1 hour. The reaction mixture was concentrated in vacuo, the residue was dissolved in diethyl ether and a precipitate formed. The suspension was stored in the fridge for 2 hours and then precipitate was collected by filtration. The collected solid was dried under high vacuum for 2 hours to give a crude yellow solid which was used without any purification. The crude solid was used to synthesize the title compound in analogy to Example 24d, using 5-Chloro-4-cyclopropylmethoxy-pyridine-2-carboxylic acid (Example 4a) as starting material and could be isolated (15 mg, 39%) as white solid; MS (ESI, m/z): 350.5 (M+H+).

Provenance & Evidence